Thermal module

ABSTRACT

A thermal module includes a heat spreader adapted for attaching to a heat-generating component, a fin unit, a heat pipe, and a securing structure for firmly pressing the heat pipe against the heat-generating component. The heat pipe includes an evaporation section attaching to the heat spreader and a condensation section attaching to the fin unit. The securing structure includes a mounting plate and a pair of bolts. Each bolt defines an annular notch in a middle thereof. The mounting plate includes a press portion and a pair of arms respectively extending from two opposite lateral sides of the press portion. A securing hole is defined in each of the arms. A plurality of tabs extend into each securing hole and snaps into the notch of a corresponding bolt with two ends of the corresponding bolt located at upper and lower sides of the securing hole.

BACKGROUND

1. Technical Field

The disclosure generally relates to thermal modules, and particularly to a securing structure of a thermal module.

2. Description of Related Art

With the continuing development of the electronic technology, electronic packages, such as CPUs, are generating more and more heat which requires immediate dissipation. A thermal module is usually mounted on the electronic component for dissipating heat generated thereby, and a securing device is needed for securing the thermal module onto the electronic component.

Generally the securing device includes a mounting plate attaching to the thermal module and a plurality of fasteners. The mounting plate defines a plurality of holes for the fasteners extending therethrough. Each fastener includes a bolt defining an annular groove near a bottom thereof, a spring disposed around a top of the bolt, and a ring-like clipping member capable of being snapped in the groove. After the bolts extend through the holes of the mounting plate, the clipping members expand radially and outwardly to snap in the grooves of the bolts, thereby pre-assembling the bolts to the thermal module.

However, during the pre-assembling process, there is no mechanism formed in the bolts which can reliably ensure the snapping of the clipping members into the grooves of the bolts; the clipping members may be mounted to screwed end portions of the bolts if the clipping members are not aligned with the grooves. When this happens, the clipping members could drop from the bolts during transportation of the pre-assembled thermal module. In addition, after the thermal module is assembled to the electronic component, the clipping members are no longer needed. As the clipping members are made of metal with good resiliency, a cost of the thermal module is increased by using the clipping members.

For the foregoing reasons, therefore, there is a need in the art for a thermal module incorporating a securing structure which overcomes the above-mentioned problems.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric, assembled view of a thermal module according to an exemplary embodiment.

FIG. 2 shows the thermal module of FIG. 1 being exploded, and viewed form another aspect.

FIG. 3 is an enlarged view of a securing structure of the thermal module of FIG. 2.

FIG. 4 shows the securing structure of the thermal module of FIG. 1 viewed from a bottom aspect.

FIG. 5 is a top plan view of the securing structure of the thermal module of FIG. 1.

DETAILED DESCRIPTION

Referring to FIG. 1, a thermal module according to an exemplary embodiment includes a blower 10, a fin unit 20, a heat pipe 30, a heat spreader 40 and a securing structure 50.

Referring to FIG. 2, the blower 10 includes a housing 12 and an impeller 18. The housing 12 includes a top wall 14, a bottom wall 16, and a sidewall 15 extending integrally and downwardly from an outer periphery of the top wall 14 to the bottom wall 16. Ears 162 are formed on the sidewall 15 and the bottom wall 16 for screws 160 extending therethrough to assemble the sidewall 15 and the bottom wall 16 together. A space 142 is defined in the housing 12 among the top wall 14, the bottom wall 16, and the sidewall 15 for receiving the impeller 18 therein.

An air inlet 140 is defined in a central portion of the top wall 14 and provided for allowing air to flow into the space 142. The sidewall 15 defines a primary outlet 150 and a secondary outlet 170 at a lateral side thereof, for allowing the air in the space to flow out the housing 12 to thereby form a forced airflow, when the impeller 14 is powered to rotate. The secondary outlet 170 is perpendicular to, and communicates with the primary outlet 150. Both of the primary outlet 150 and the secondary outlet 170 are perpendicular to the air inlet 140 of the top wall 14. The primary outlet 150 is much larger than the secondary outlet 170. The secondary outlet 170 is positioned near a tongue (not labeled) of the blower 10 which extends inwardly from the sidewall 15 into the space 142. A guiding plate 17 extends outwardly from a junction of the primary outlet 150 and the secondary outlet 170. The secondary outlet 170 is defined between the guiding plate 17 and the tongue of the sidewall 15.

The fin unit 20 is arranged at the primary outlet 150 of the blower 10. The heat spreader 40 is a flat block, which is made of copper or its alloy. The heat spreader 40 has a planar top surface 42 and a planar bottom surface 44 for attaching to a heat-generating component 80, such as a CPU. Four through holes 46 extend through the heat spreader 40 from the top surface 42 to the bottom surface 44. The four through holes 46 are respectively formed at four corners of an imaginary rectangle. The heat pipe 30 includes an evaporation section 32 and a condensation section 34 formed at two ends thereof, respectively. The evaporation section 32 attaches to the top surface 42 of the heat spreader 40, and the condensation section 34 attaches to a bottom of the fin unit 20. Thus heat generated by the heat-generating component 80 can be transferred to the fin unit 20 by the heat spreader 40 and the heat pipe 30; finally the forced airflow of the blower 10 can take the heat to an outside of the fin unit 20.

Referring to FIGS. 3-5, the securing structure 50 is used to press the heat spreader 40 of the thermal module to the heat-generating component 80 firmly, and thus a heat conduction between the heat-generating component 80 and the heat spreader 40 of the thermal module can be attained. The securing structure 50 includes a mounting plate 52 and a pair of bolts 58. Each bolt 58 includes a head portion 581 at a top end, a threaded portion 583 at a bottom end, and an engaging portion 582 between the head portion 581 and the threaded portion 583. An inner thread 580 is defined in an inner surface of the threaded portion 583 of the bolt 58. The head portion 581 has a diameter larger than that of the threaded portion 583, whilst the engaging portion 582 has a diameter smaller than that of the threaded portion 583. Therefore an annular notch 584 is defined around the engaging portion 582 between the threaded portion 583 and the head portion 581.

The mounting plate 52 is elongated, and includes a press portion 53 and a pair of arms 54 formed at two opposite sides of the press portion 53, respectively. The press portion 53 is generally n-shaped, and includes a press wall 532 and a pair of legs 534 extending downwardly from the press wall 532. A width of the press wall 532, i.e., a distance between the two legs 534, is substantially the same as a width of the heat pipe 30. A height of each leg 534 is substantially the same as that of the heat pipe 30. An aperture 531 is defined in a middle of the press portion 53.

The arms 54 extend outwardly and slightly upwardly from bottom ends of the pair of legs 534, respectively. A free end 55 of each arm 54 is a little higher than the bottom ends of the legs 534, whilst a little lower than the press wall 532 of the press portion 53. A rib 551 is formed at a bottom side of an outer periphery of the free end 55 of each arm 54 for enhancing a strength of the arm 54 of the securing structure 50. Each arm 54 defines a pair of mounting holes 530 adjacent to the press portion 53. The four mounting holes 530 of the two arms 54 are aligned with the through holes 46 of the heat spreader 40. Thus rivets (not shown) can extend through the mounting holes 530 of the arms 54 of the securing structure 50 and the through holes 46 of the heat spreader 40 to fixedly assemble the securing structure 50 to the heat spreader 40.

A securing hole 552 is defined in each arm 54 near the free end 55 thereof for extension of the bolts 58. The securing holes 552 are generally circular. A diameter of each securing hole 552 is smaller than that of the head portion 581 of the bolt 58, but is not smaller than that of the threaded portion 583 of the bolt 58. A plurality of elastic tabs 553 extend inwardly and downwardly from each arm 54 at a position around the securing hole 552. The tabs 553 of each arm 54 are spaced from each other. Each tab 553 has an arc-shaped inner side slightly lower than the arm 54. Cooperatively the inner sides of the tabs 553 of each arm 54 define a circle 554 with a diameter which is smaller than that of the threaded portion 583, and is not smaller than that of the engaging portion 582 of the bolt 58. Preferably, the diameter of the circle 554 equals to that of the engaging portion 582 of the bolt 58.

During assembly, the fin unit 20 is arranged at the primary outlet 150 of the blower 10. The mounting plate 52 of the securing structure 50 is secured onto the heat spreader 40 by rivets. A passage is thus defined between the press wall 532 of the press portion 53 of the mounting plate 52 and the top surface 42 of the heat spreader 40 with the evaporation section 32 of the heat pipe 30 extending therethrough. The condensation section 34 of the heat pipe 30 is fixed to the fin unit 20 by soldering. The bolts 58 are pressed to move downwardly to engage into the securing holes 552 of the arms 54 of the securing structure 50. Thus the thermal module is pre-assembled together. When assembling the thermal module to the heat-generating component 80, the bolt 58 is pressed and continuously rotated to cause the threaded portion 583 completely threadedly engaging with a threaded pin (not shown) of a back plate (not shown) attached to a bottom of a circuit board 90. The heat-generating component 80 is mounted on a top of the circuit board 90. Thus, the heat-generating component 80 is sandwiched between the circuit board 90 and the heat spreader 40 of the thermal module, and intimately contacts with the heat spreader 40 for dissipation of heat through the thermal module.

As the elastic tabs 553 slant downwardly, the elastic tabs 553 in each securing hole 552 deform to enlarge a space therebetween for enabling the threaded portion 583 of the corresponding bolt 58 to extend through the securing hole 552 when the threaded portion 583 of the bolt 58 engages the elastic tabs 553 during movement of the bolt 58 in the pre-assembly of the thermal module. After the threaded bolt 58 passing through the securing hole 552, the elastic tabs 553 resume to their free state, and thus snap into the notch 584 around the engaging portion 582 of the bolt 58. Since the threaded portion 583 of the bolt 58 is larger than the space between the tabs 553 at free, the bolt 58 can not move upwardly through the securing hole 552. In addition, as the diameter of the head portion 581 of the bolt 58 is larger than the securing hole 552, the head portion 581 of the bolt 58 can not move downwardly through the securing hole 552 of the arm 54 of the securing structure 50. The bolts 58 pre-assembled to the arms 54 of the securing structure 50 of the thermal module thus can not escape from the thermal module.

In the embodiment, since the bolts 58 can be assembled to the securing structure 50 directly, the bolt 58 can have a simple structure and accordingly a low cost. The clipping members of the conventional art are not necessary in the present invention, and thus assembly of the clipping members to the bolts 58 is no longer needed. Accordingly, the present invention does not have the disadvantage of the conventional art that the clipping members may engage with the threaded portions 583 and drop from the bolts 58. Finally, the assembly of the bolts 58 to the heat dissipation device can be more quickly completed than the conventional art.

It is to be understood, however, that even though numerous characteristics and advantages of the disclosure have been set forth in the foregoing description, together with details of the structure and function of the disclosure, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. 

1. A thermal module, comprising: a heat spreader adapted for attaching to a heat-generating component to absorb heat therefrom; a fin unit; a heat pipe having an evaporation section attaching to the heat spreader and a condensation section attaching to the fin unit for transferring heat from the heat spreader to the fin unit; and a securing structure adapted for firmly pressing the heat pipe against the heat-generating component, the securing structure comprising a mounting plate and a pair of bolts, each bolt defining an annular notch in a middle thereof, the mounting plate comprising a press portion attaching to the heat pipe and a pair of arms respectively extending from two opposite lateral sides of the press portion, a securing hole being defined in each of the arms for engaging with a corresponding bolt, a plurality of tabs extending into each securing hole from the arm around the securing hole, the tabs snapping into the notch of the corresponding bolt with two ends of the corresponding bolt located at upper and lower sides of the securing hole.
 2. The thermal module of claim 1, wherein each bolt comprises a head portion, a threaded portion and an engaging portion between the head portion and the threaded portion, a diameter of the threaded portion being smaller than that of the head portion and being larger than that of the engaging portion, the notch is defined around the engaging portion.
 3. The thermal module of claim 2, wherein each tab has an arced inner side, cooperatively the arced inner sides of the tabs in each securing hole defines a circle with a diameter smaller than that of the threaded portion and not smaller than that of the engaging portion of the corresponding bolt.
 4. The thermal module of claim 3, wherein the diameter of the circle defined by the arced inner sides of the tabs in each securing hole substantially equals to that of the engaging portion of the corresponding bolt.
 5. The thermal module of claim 3, wherein the diameter of the securing hole is not smaller than that of the threaded portion, and is smaller than that of the head portion of the bolt.
 6. The thermal module of claim 2, wherein an inner thread is defined in an inner surface of the threaded portion of the corresponding bolt adapted for threadedly engaging with a threaded pin.
 7. The thermal module of claim 1, wherein each securing hole is defined near a free end of the arm, and a rib is formed at an outer periphery of the free end of the arm for enhancing a strength of the arm of the securing structure.
 8. The thermal module of claim 1, wherein the press portion comprises a press wall and a pair of legs extending downwardly from opposite lateral sides of the press wall, the arms respectively extending slightly upwardly from bottom ends of the legs, a free end of each arm being higher than the bottom ends of the legs and lower than the press wall.
 9. The thermal module of claim 8, wherein the evaporation section of the heat pipe abuts the press wall and the heat spreader at two opposite sides thereof, respectively, an aperture being defined in a middle of the press wall.
 10. The thermal module of claim 1, further comprising a blower defining an air inlet, a primary outlet and a secondary outlet, the primary outlet and the secondary outlet being perpendicular to the air inlet, the primary outlet being perpendicular to and having a size much larger than the secondary outlet, the fin unit being arranged at the primary outlet.
 11. A securing structure, comprising: a pair of bolts, each bolt defining an annular notch in a middle thereof; and a mounting plate comprising a press portion and a pair of arms respectively extending from two opposite lateral sides of the press portion, a securing hole being defined in each of the arms, a plurality of tabs extending into each securing hole from the arm around the securing hole, the tabs snapping into the notch of a corresponding bolt with two ends of the corresponding bolt located at upper and lower sides of each of the arms.
 12. The securing structure of claim 11, wherein each bolt comprises a head portion, a threaded portion and an engaging portion between the head portion and the threaded portion, a diameter of the threaded portion being larger than that of the engaging portion and being smaller than that of the head portion, the notch being defined around the engaging portion, the diameter of the securing hole being smaller than that of the head portion and not smaller than that of the engaging portion of each bolt, each tab having an arced inner side, cooperatively the arced inner sides of the tabs in each securing hole defines a circle with a diameter smaller than that of the threaded portion of each bolt and not smaller than that of the engaging portion of each bolt.
 13. The securing structure of claim 12, wherein each tab extends aslant from the arm into the engaging hole, the arced inner side of each tab is lower than the arm.
 14. The securing structure of claim 12, wherein the circle defined by the inner sides of the tabs in each securing hole has a diameter substantially equaling to that of the engaging portion of the bolt.
 15. The securing structure of claim 12, wherein an inner thread is defined in an inner surface of the threaded portion of each bolt, adapted for threadedly engaging with a threaded pin.
 16. The securing structure of claim 11, wherein each securing hole is defined near a free end of the arm, and a rib is formed at an outer periphery of the free end of the arm for enhancing a strength of the arm of the securing structure.
 17. The securing structure of claim 11, wherein the press portion comprises a press wall and a pair of legs extending downwardly from two opposite lateral sides of the press wall, the arms respectively extending slightly upwardly from bottom ends of the legs, a free end of each arm being higher than the bottom ends of the legs and lower than the press wall. 